Mrange 190 nm to 24 microns with quick interchange gratings, min. Bandpass 0.25 nm with 2400 1/mm grating, reciprocal dispersion 3.2 nm/mm for 2400 1/mm grating, focal length-125 mm, wavelength readout dial range-0 to 1000 nm with 1200 1/mm grating, wavelength dial range 0 to 1000 nm with 1200 1/mm grating, wavelength dial accuracy-dial is adjustable, mounting by 1/4-20 tapped hole in bottom centered between slits by four 4-40 tapped holes in bottom or on four rubber feet